Top 20 String qstns Flashcards
1
Q
- What is String in Java? Is it a datatype?
A
..
2
Q
- What is the difference between String in C language and String in Java?**
A
..
3
Q
- What is the String pool in Java?**
A
.
4
Q
- Why String is immutable?**
A
.
5
Q
- How many objects will be created from the following code?**
A
.
6
Q
- What is the
intern()method?**
A
..
7
Q
- What is the difference between the**
StringandStringBuffer?
A
..
8
Q
- What is the difference between the**
StringBufferandStringBuilder?
A
.
9
Q
- Can we compare String using the
==operator? What is the risk?**
A
.
10
Q
- What are the ways to compare string?**
A
.
11
Q
- What is the use of the
substring()method?**
A
.
12
Q
- How to check if the String is empty?**
A
.
13
Q
- What is the
format()method in Java String? What is the difference between theformat()method and theprintf()method?**
A
.
14
Q
- Can you say String is ‘thread-safe’ in Java?**
A
Yes, we can say that the string is thread-safe.
As we know, String is immutable in Java. That means once we created a string, we can not modify it afterword. Hence there is no issue of multiple threads accessing a string object.
15
Q
- Why most of the time string is used as
HashMapkey?**
A
.
16
Q
- Can you convert String to Int and vice versa?**
A
.
17
Q
- What is the
split()method?**
A
.
18
Q
- What is the difference between
"Gaurav Kukade".equals(str)andstr.equals("Gaurav Kukade")?**
.
A
.
19
Q
- Can we use a string in switch case in java?**
A
.
20
Q
- How string concatenation using the
+operator works in Java?**
A
+operator is the only overloaded operator. You can use it for both adding two numbers as well as for string concatenation purposes.
If you are using the Java version 1.5 or above, string concatenation internally uses the`append()`method of the`StringBuilder`. And for versions lower than 1.5, it uses the`append()`method of the`StringBuffer`class
